Studies on the Antimicrobial Activity of Chitooligosaccharides from Housefly Larvae, Musca domestica vicina Macquart(Diptera: Muscidae)

The inhibition effect of chitooligosaccharides from housefly larvae on pathogens ofcrops seeds, fruits or vegetables was studied and the main factors influencing theantimicrobial activity of chitooligosaccharides were also investigated. It was foundthat chitooligosaccharides from housefly larvae had wide spectrum fungistasis. It canstrongly inhibit the development of 31 kinds of plant pathogenic fungi such as corticiumrolfsii Saccardo. The results indicated that the degree of deacelylation (DD) or theaverage molecular weight(MW)of chitooligosaccharides were related to the antimicrobialactivity. The antimicrobial activity increased with the rising of DD or the declining ofMW. Pot culture results showed that chitooligosaccharide could enhance the rate ofgermination and emergence of the seeds of maize, wheat and cotton. Chitooligosaccharidehad certain effect on corn southern leaf blight caused by Helminthosporium maydis.

蝇蛆几丁低聚糖抑菌作用的初步研究

研究了蝇蛆几丁低聚糖对主要农作物种子病原菌和一些果蔬腐烂菌的抑制作用,并探索影响其抗菌活性的主要因子。结果表明,蝇蛆几丁低聚糖具有广谱的抗菌活性,对测试的32种农作物病原真菌和果蔬腐烂真菌中的花生白绢菌等31种有较好的抑制作用;蝇蛆几丁低聚糖的抗菌活性与脱乙酰度和分子量大小有关,随着脱乙酰度的增加,几丁低聚糖的抗菌活性逐渐增强,随着分子量的增大,几丁低聚糖的抗菌活性逐渐下降。盆栽试验结果表明,蝇蛆几丁低聚糖处理玉米、小麦和棉花种子,可以提高发芽率和出苗率。蝇蛆几丁低聚糖喷雾处理对玉米苗期小斑病具有一定的防病效果。

蝇蛆几丁低聚糖对花生白绢病菌菌丝形态及超微结构的影响

研究了蝇蛆几丁低聚糖对花生白绢病菌菌丝形态及细胞超微结构的影响,结果表明:蝇蛆几丁低聚糖对花生白绢病菌具有很好的抑制作用,质量浓度7.0mg/mL时抑菌效果达到了100％;显微镜下可观察到蝇蛆几丁低聚糖处理引起菌丝顶端膨大,生长扭曲,菌丝内原生质体分布不均匀,部分细胞甚至开始解体;透射电镜观察发现蝇蛆几丁低聚糖处理导致菌丝内原生质体液泡化,出现电子致密物质,原生质膜部分收缩,液泡内有电子致密物质沉积,液泡逐渐融合成大型液泡,细胞受到严重破坏,甚至解体等一系列细胞超微结构的变化。

蝇蛆几丁低聚糖对草莓保鲜作用研究

两种蝇蛆几丁低聚糖对7种草菌病原菌的抑制作用,试验结果表明酶解几丁低聚精的抑菌活性显著高于H_2O_2水解几丁低聚糖,质量浓度10g/ml时,它对草莓灰霉菌等6种病原菌有强烈的抑制作用,抑菌效果在80％以上,但对草莓白粉菌的抑制作用一般;H_2O_2水解几丁低聚糖对草莓灰霉菌等4种病原菌也有很好的抑制效果,对草莓黑霉病菌等3种病原菌的抑制作用较差。盆栽试验结果表明蝇蛆几丁低聚糖喷雾处理可以减少生长期草莓果实的发病率,处理后第3天即表现出一定的防病效果,处理后第6天防病效果最佳,处理后第9天,防病效果开始有所下降。涂膜处理试验结果表明,在常温下,10～20mg/ml几丁低聚糖溶液处理,可使草莓的保存期延长2～3天。